Description
The conserve mode self protections mechanisms will be changed in 5.6, main differences are :
- no more distinction between "kernel" versus "Proxy" or "system" types of conserve mode
- definition of 3 thresholds "green", "red", "extreme", all adjustable via CLI
- trigger based on "memory used"
- new event logs
- new diagnose command "diagnose hardware sysinfo conserve"
- new conserve mode stats in proxy stats via "diag sys proxy stats all (see conserve_mode line)
- 3 memory thresholds : red, extreme and green
'red' and 'extreme' : Both 'red' and 'extreme' are thresholds to enter in 'conserve mode' when the system memory used is over their thresholds.
When the used memory goes over the defined red threshold, the kernel raises the conserve mode state. FortiGate functions reacting to conserve mode state, like antivirus transparent proxies, would apply their own restriction based on their settings.
If used memory continues to increase and reach the 'extreme' threshold, conserve mode action taken with the red threshold are still active and additionally new sessions will be dropped.
'green' : When used memory goes below the 'green' threshold, kernel releases the conserve mode state. FortiGate functions reacting to conserve mode state would stop their restriction measures.
Though it is recommended to keep the default memory threshold, a new CLI command has been added to allow administrators to adjust the thresholds.
Default values are :
- red : 88% of total memory is considered "used memory"
- extreme : 95% of total memory is considered "used memory"
- green : 82% of total memory is considered "used memory"
- configuration (CLI only) :
set memory-use-threshold-extreme 95
set memory-use-threshold-red 88
set memory-use-threshold-green 82
FGVM # diagnose hardware sysinfo conserve
memory conserve mode: off
memory used: 448 MB 45% of total RAM
memory used threshold extreme: 944 MB 95% of total RAM
memory used threshold red: 874 MB 88% of total RAM
memory used threshold green: 815 MB 82% of total RAM
Internal Notes
This conserve mode change was originally planned for 5.4.2 but has been moved to 5.6 now
